It is known to use a plasma cutter to cut a material, such as, for example only, steel, sheet metal, aluminum, and the like. In general, plasma cutting is performed by projecting an inert gas or compressed air from a source through a plasma torch nozzle towards the surface of the material to be cut, and simultaneously driving an electrical current through the gas or air by applying a voltage between the cutter and the material to form a plasma within the projected gas or air. The generated plasma is hot enough that it can be used to cut a variety of different materials.
In general plasma cutting systems typically include a power supply, ground, and a torch and can be used manually to cut the material. However, Computer Numerical Controlled (CNC) plasma cutting systems employ additional hardware and software to facilitate automated and often more precise material cutting. An exemplary system uses control hardware and software along with rails, carriages, gantries and stepper motors to control the motion along the movement axis for precision cutting. Exemplary embodiments of a plasma cutter and material are shown in FIGS. 1 and 2.
When a plasma cutter first turns on and begins cutting a material, it takes time for the plasma jet to pierce through the material (i.e., to achieve an adequate Z-plane depth of the cut). During this time, the plasma needs to stay stationary with respect to the material before it can be moved to continue the cutting of the material (i.e., in the XY plane). The time for this initial piercing can vary according to the properties and thickness of the material to be cut, along with the characteristics of the plasma cutting device, such as, the power of the plasma system, nozzle geometry, and other factors.
One known method for determining the amount of time for this initial piercing to occur is to estimate the amount of time based on past experimental data, which can be then used to create a look-up table based on the characteristics of the material and of the plasma cutting system. However, such look-up tables can be imprecise resulting in insufficient cutting. If the time given in the table is too long, there will be a larger-than-desired dilated hole at the beginning of the cut. If the time in the table is too short, the plasma may not cut all the way through the material at the beginning of a cut. Also, the look-up table may not take into account variable thicknesses in the material being cut.
There is therefore a need for an improved system, device, and method for determining the proper amount of time to spend at a cutting location with a plasma cutter.